The historic 150-year-old Las Flores Adobe at Camp Pendleton, a registered National Historic Landmark, is open for tours starting Friday, April 6.

The building sits at the northern end of the base near the Las Pulgas exit not far from Interstate 5, about 14 miles north of the Rancho Santa Margarita y Las Flores Ranch House, which dates back to the 1820s and is listed on the National Register of Historic Sites.

The two-story adobe hacienda was built in 1868 and is an example of California “Monterey style” architecture.

“The Las Flores Adobe is one of a small number of surviving 19th-century Monterey Colonial style residences,” said Barbara Greenbush, a member of the Rancho Santa Margarita y Las Flores Docents, which give tours at the Santa Margarita Ranch House and Las Flores Adobe. The nonprofit group works with the Camp Pendleton Historical Society and the Marine Corps base to restore the buildings and preserve the base’s history.

“The story of Las Flores Adobe is common in California history,” Greenbush said. “The land the adobe is on was once part of a Spanish mission, then became part of a private Mexican ranch, and later was incorporated into a smaller ranch after the U.S.-Mexican War in the late 1840s.”

The 45-minute tour outlines the history of the adobe going back to when the land was part of Mission San Luis Rey and later when a land grant of more than 133,440 acres north of the Mission, known as Rancho Santa Margarita y Las Flores, was given to Pio Pico, the last Mexican governor of Alta California in 1841.

Tour guides describe how the adobe and the land changed hands over the years, including how Pico sold Rancho Santa Margarita y Las Flores to his brother-in-law, John “Don Juan” Forster in 1864, who built up a thriving cattle ranch. It is believed that his son, Marcos Forster, built the Las Flores Adobe for his wife and family.

Ownership changed hands in 1888, when Richard O’Neill and James L. Flood bought Rancho Santa Margarita y Las Flores and hired the Magee family to manage the ranch. In the 1880s, the adobe was leased to the family of Jane Magee (known as the “Bean Queen”), who raised lima beans on the land.

The U.S. government bought the land and opened Camp Pendleton in 1942 to train Marines.

Visitors can also take a 45-minute tour of the adobe ruins of Las Flores Estancia, built circa 1817 about 200 yards west of the hacienda. Catholic priests and other travelers rested at the estancia while traveling between Mission San Luis Rey and Mission San Juan Capistrano.

After April 6, tours will continue the fourth Tuesday of every month. The next tour is on May 22. Visitors are advised to wear closed-toed walking shoes for the tours.

Tour reservations are required at (760) 725-5758 or MCBCAMPEN_history@usmc.mil.